The present disclosure relates generally to improved clutch systems, and more particularly to clutch systems featuring a plurality of ported oiling holes in the inner hub and a control diaphragm to contain the oil.
In general, multi-disc wet clutch transmissions have a plurality of friction plates capable of engaging with one another. Transmissions that utilize a multi-disc wet clutch system typically have a limited amount of clutch allocated lubricant (oil) volume. This limited volume must be used in the most efficient and direct point placement to minimize the consumption of volume from the pump system that provides pressure and volume to the entirety of the transmission demands for gear and bearing lubrication. Typically the inner clutch hub is a forged or cast shape ported with oil from one side. This oil that is ported in, flows across inner hub and cools the inner surface profile of the clutch hub. With inadequate lubricant placement or volume, multi-disc wet clutch systems will run near dry, overheat, and cause friction material failure.
In order to overcome these problems, various solutions have been introduced. For example, some designs have fluid holes drilled through the inner hub to allow a small percentage of the oil to centrifugally pass directly into the clutch plates. In this scenario, a majority of the oil is expelled out the large opening due to the design aspect and the lofted interior surfaces created for the mold/production and part ejection process during manufacturing. In many other applications, the clutch assembly actually sits in an oil bath or is sprayed from a port or ports to the outer surface of the clutch assembly. As elevated rpm is introduced, the clutch assembly cuts through the oil creating parasitic friction loss, foaming, and lubrication is centrifugally thrown off.
As such, there is a need for a system to continuously oil and cool a wet clutch system at all engagement or modulation rpm ranges with a limited amount of lubricant volume. There is a need for such a system that allows for every friction plate to be sufficiently lubricated, while also minimizing system drag, parasitic friction loss, foaming, and other undesirable effects from the use of excess lubricant.